Dynamo-electric machine.



No. 706,!08. Patented Aug. 5, I902. H. G. REIST.

DYNAMO ELECTRIC MACHINE.

(Application filed Nov. 13, 1900.) (No Model.) 2 Sheeta$haet l.

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" Henry GReist,

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6 n r n H Witnesses UNITED STATES PATENT OFFICE.

HENRY G. REIST, OF SOIIENEOTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEV YORK DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 706,108, dated August 5, 1902. Application filed November 13,1900. Serial No. 86,368. (No model.)

T at whom it may concern: short-circuiting of the field-flux. I find that Be it known that I, HENRY G. REIsT, acitithe presence of this bridge makes the coinzen of the United States, residing at Schenecpounding more regular. tady, county of Schenectady, State of New My invention comprises other features of 55 York, have invented certain new and useful novelty and possesses various advantages, all Improvements in Dynamo-Electric Machines, of which will be pointed out in the following (Case No. 1,278,) of which the following is a description, which is to be taken in connecspecification. tion with the accompanying drawings.

My present invention comprises certain im- The points of novelty of my invention are 60 1o provements embodied in an alternating-cur i particularly set forth in claims appended rent dynamo-electric machine now well known hereto. in the art as a compensated alternator. In the drawings, Figure 1 represents aside The principles of operation of a machine of elevation, partly in section, of a machine emthis type are set forth at length in a patent bodying myinvention. Fig. 2 is an end view 65 I5 granted on an application of E. W. Rice, Jr., of the same, while Fig. 3 is a diagram useful No. 595,412, December 14-, 1897, the claims of in explaining the connections and mode of opwhich patent broadly cover the type of maeration of the machine. chine mentioned. Such a machine, as will be Referring first to the structure of the maevident from an inspection of the patent menchine as indicated in Fig. 1, it will be seen to 70 2o tioned, comprises as its principal feature an consist in its main features of a solidly-built alternatingcurrent generator the field of supporting frame 1, carrying the induced which is supplied with direct current from a member 2 of an internal revolving-field altersynchronously-driven exciter. The voltage nator and the field-magnet structure 3 of a of the exoiter is automatically controlled by direct current exciter, the armature at of 7 5 z 5 passing current derived from the main alterwhich is mounted upon the same shaft as the nator through the armature of the eXciter, revolving-field structure 5 of the main alterthereby varying the armature reaction of the nator. No detailed description of the struceXciter, which in turn varies the field strength ture of this alternator is necessary, since the and regulates the voltage. The alternating same may be of any usual and suitable char- 8o current is fed to the eXciter in such a manacter. I prefer, however, to employ a type nor as to produce in the armature-winding a of alternator in which the field revolves, rotating magnetic field moving with'respect since thereby I obtain certain mechanical to the armature in a direction opposite from and electrical advantages not necessary to the direction of rotation of the armature. As describe herein. 8 5 the exciter-armature moves forward with the The yoke or frame 6, carrying the fieldsame speed with which the rotary field therein magnet poles and field-spools of the exciter, moves backward,the field as a consequence reis provided with an annular bearing 7, formed mains stationary in space as long as the power upon the inwardly-extendin g curved flange 8, factor of the load remains constant. To seconstituting one of the side pieces of the main 90 40 cure the necessary initial adjustments of this frame 1 of the machine. This circular flange field with respect to the field-magnets upon 8 or side portion of the frame is extended outwhich in practical operation it reacts, I have ward at 9, so as to form a support for the devised a structure in which the field-n1agbearings forone end of the main shaft 10, the

nets of the exciter are mounted so that they other end of which is similarly supported in 5 may be angularly displaced, thereby adjustbearings carried in like manner by another ing the angle at which the armature-flux is rounded flange or side portion 10, attached permitted to act upon the field. to the main frame 1.

Another feature of my invention consists Returning to the description of the yoke 6,

in bridging overthe field-poles of the exciter it will be seen that the same is provided with ICO by a band of magnetic material, which by arecessedbearing-surface 7, extending along reason of saturation does not allow an undue the outer surface of the ring and terminating in an angular ledge 11 at right angles to the surface 7. When the yoke 6 is in place in its bearing in the side piece 8, thisledge abuts against the side portion of the side piece 8 and permits the yoke and the parts supported thereby to be firmly secured in place by clamping-bolts 12 and 13, the heads of which are indicated in Fig. 2. By loosening these bolts the eXciter-field may he slid backward or forward in its bearings, and when a desired position of the same is reached it may be clamped securely in position, as will be evident.

The field-poles of the exciter are all connected together mechanically by a thin ring 15, of magnetic material, preferably cast-iron, extending across and between all of the polefaces. The object of this ring, as has already been explained, is to improve the automatic regulating action of the machine, and this it does by rendering the regulating etfect less abrupt during one portion of the range of reg ulation. At the same time the ring serves as a mechanical support for the field-coils.

The armature of the eXciter is shown at 4 and is provided with an ordinary winding of the direct current type connected in the usual manner to a commutator 16, upon which bear brushes, which for convenience in illustration are shown conventionally in dotted lines at 17.

Mounted beside the commutator 16 is a pair of collector rings, (indicated at 18.) The brushes bearing upon these collector-rings are also conventionally indicated by dotted lines 19. These collector-rin gs are electrically connected to the terminals of the exciting-winding of the revolving-field magnet structure 5 of the main alternator and serve to convey the exciting-current thereto.

Mounted upon an outboard end of the shaft 10 are three more collector-rings. (Indicated in Fig. 1 at 20.) These collector-rings are connected in three-phase relation with the armature-winding of the eXciter-armature 4 and serve to convey thereto alternating current derived from the induced member 2 of the main alternator.

The main terminals of the alternator are indicated at 21. From these terminals connections are made leading to the primary windings of a set of series transformers, through which the current from the alternator is conveyed to suitable consumptioncircuits. The secondaries of these series transformers are connected to terminals 22, shown in Fig. 2 as projecting from an opposite side of the machine from the main terminals, the terminals extending within the frame and emerging therefrom at 23, where they make connection with suitable brushes (not shown) bearing upon the collector-rings 20. The connections thus roughly described will be better understood by reference to the diagram Fig. 3. For convenience this diagram represents the circuits ofa compensated alternator of four poles, although in Figs. 1

and 2 it will be seen the machine has eight poles. The principle of operation, however, is the same, regardless of the number of poles.

Referring more in detail to the diagram, it will be seen that the compensated alternator consists of two machines, the main alternator at at and the exciter25. The main alternator consists of a four-pole revolving field 35, excited by direct current conveyed over the lines 26, this revolving field being located in inductive relation to a fixed induced member 27, provided with any suitable windingas, for example, a distributed three-phase winding connected to terminals 28. From these terminals mains lead to the primaries 29 of a set of series transformers, after traversing which primaries they extend to suitable consumption-circuits. The secondaries 30 of the series transformers are connected togetheras, for example, by a Y connection-*and then to collector-rings 31, by which the current from the secondaries is conveyed to the armature 32 of the exciter 25, into the Winding of which the curreutpasses by means of con nections in three-phase relation so interrelated as to produce a field rotating about the armature in a direction opposite the direction of rotation of the armature itself. The armature 32 of the exoiter being caused to 1'0- tate synchronously with the revolving-field magnet 35 by some suitable meansas, for example,by bei ng mounted on a common shaft (indicated conventionally by dotted lines 33)--the rotating field set up in the armature winding of the exciter assumes a position in space which is stationary except for a varied shifting angular displacement back or forth, depending upon the amount of lag or lead of the alternating current sent into the winding through the collector-rings 31 in the manner already described. This armature reaction due to the alternating current operates to strengthen or weaken the field of the exciter, thereby producing corresponding regulation of the main alternator 24 in a manner set forth at length in the above-mentioned patent.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is

1. The combination of an internal revolving-field alternator, an eXciter or regulatingmachine therefor having its armature synchronously rotatable with the revolving-field member of the alternator, collector-rings connected to said armature, and other collector-rings connected with said revolving-field member.

2. The combination of an internalrevolving-field alternator, an exciter or regulatingmachine therefor having its armature mount ed on the same shaft as the revolving-field member of the alternator, and means for angularly adjusting the field of the exciter.

3. A dynamo-electric machine consisting of a main machine and an exciter therefor with the revolving members of each mounted on the same shaft, and means for moving the field of the exciter relatively to the fixed member of the main machine.

4. The combination of a main machine, a synchronously-driven exoiter therefor, and means for adjusting the exciter-field relatively to the fixed member of the main machine.

5. The combination of a main machine, an exciter therefor having a field-magnet structure provided with pole-pieces, bridges of magnetic material extending between said pole-pieces, and means for adjusting the exciter-field relatively to the fixed member of the main machine.

6. A compensated alternator consisting of a main machine of the revolving-field type, an exciter or regulating-machine therefor having its armature and commutator mounted on the same shaft as the revolving member of the main machine, collectonrings connected to points in the winding of said armature, and other collector-rings connected to the winding of the revolving field of the main machine.

7. A compensated alternator consisting of a main machine of the revolving-field type, an exciter or regulating machine therefor having its armature and commutator mounted on the same shaft as the revolving member of the main machine, collector-rings connected to points in the winding of said armature, other collector-rings connected to the winding of the revolving field of the main machine, and a rigid supporting structure or frame for carrying the fixed members of both machines.

8. A compensated alternator comprising a main machine, an exciter therefor, a single shaft upon which the revolving member of the main machine and armature of the exoiter are both mounted, and means for shifting the field structure of the exciter relatively to the fixed portion of the main machine.

In witness whereof I have hereunto set my hand this 12th day of November, 1900.

HENRY G. REIST.

Witnesses BENJAMIN B. HULL,- MABEL I-I. EMERSON. 

